randfile.c

/* crypto/rand/randfile.c *//* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] *//* We need to define this to get macros like S_IFBLK and S_IFCHR */#define _XOPEN_SOURCE 500#include <errno.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include "e_os.h"#include <openssl/crypto.h>#include <openssl/rand.h>#include <openssl/buffer.h>#ifdef OPENSSL_SYS_VMS#include <unixio.h>#endif#ifndef NO_SYS_TYPES_H# include <sys/types.h>#endif#ifdef MAC_OS_pre_X# include <stat.h>#else# include <sys/stat.h>#endif#undef BUFSIZE#define BUFSIZE 1024#define RAND_DATA 1024/* #define RFILE ".rnd" - defined in ../../e_os.h *//* Note that these functions are intended for seed files only. * Entropy devices and EGD sockets are handled in rand_unix.c */int RAND_load_file(constchar *file, long bytes)
{
/* If bytes >= 0, read up to 'bytes' bytes. * if bytes == -1, read complete file. */
MS_STATIC unsignedchar buf[BUFSIZE];
struct stat sb;
int i,ret=0,n;
FILE *in;
if (file == NULL) return(0);
if (stat(file,&sb) < 0) return(0);
RAND_add(&sb,sizeof(sb),0.0);
if (bytes == 0) return(ret);
in=fopen(file,"rb");
if (in == NULL) goto err;
#if defined(S_IFBLK) && defined(S_IFCHR)if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
/* this file is a device. we don't want read an infinite number * of bytes from a random device, nor do we want to use buffered * I/O because we will waste system entropy. */
bytes = (bytes == -1) ? 2048 : bytes; /* ok, is 2048 enough? */
setvbuf(in, NULL, _IONBF, 0); /* don't do buffered reads */
}
#endiffor (;;)
{
if (bytes > 0)
n = (bytes < BUFSIZE)?(int)bytes:BUFSIZE;
else
n = BUFSIZE;
i=fread(buf,1,n,in);
if (i <= 0) break;
/* even if n != i, use the full array */
RAND_add(buf,n,(double)i);
ret+=i;
if (bytes > 0)
{
bytes-=n;
if (bytes <= 0) break;
}
}
fclose(in);
OPENSSL_cleanse(buf,BUFSIZE);
err:
return(ret);
}
int RAND_write_file(constchar *file)
{
unsignedchar buf[BUFSIZE];
int i,ret=0,rand_err=0;
FILE *out = NULL;
int n;
struct stat sb;
i=stat(file,&sb);
if (i != -1) {
#if defined(S_IFBLK) && defined(S_IFCHR)if (sb.st_mode & (S_IFBLK | S_IFCHR)) {
/* this file is a device. we don't write back to it. * we "succeed" on the assumption this is some sort * of random device. Otherwise attempting to write to * and chmod the device causes problems. */return(1);
}
#endif }
#if defined(O_CREAT) && !defined(OPENSSL_SYS_WIN32) {
/* For some reason Win32 can't write to files created this way *//* chmod(..., 0600) is too late to protect the file, * permissions should be restrictive from the start */int fd = open(file, O_CREAT, 0600);
if (fd != -1)
out = fdopen(fd, "wb");
}
#endifif (out == NULL)
out = fopen(file,"wb");
if (out == NULL) goto err;
#ifndef NO_CHMOD chmod(file,0600);
#endif n=RAND_DATA;
for (;;)
{
i=(n > BUFSIZE)?BUFSIZE:n;
n-=BUFSIZE;
if (RAND_bytes(buf,i) <= 0)
rand_err=1;
i=fwrite(buf,1,i,out);
if (i <= 0)
{
ret=0;
break;
}
ret+=i;
if (n <= 0) break;
}
#ifdef OPENSSL_SYS_VMS/* Try to delete older versions of the file, until there aren't any */
{
char *tmpf;
tmpf = OPENSSL_malloc(strlen(file) + 4); /* to add ";-1" and a nul */if (tmpf)
{
strcpy(tmpf, file);
strcat(tmpf, ";-1");
while(delete(tmpf) == 0)
;
rename(file,";1"); /* Make sure it's version 1, or we will reach the limit (32767) at some point... */
}
}
#endif /* OPENSSL_SYS_VMS */
fclose(out);
OPENSSL_cleanse(buf,BUFSIZE);
err:
return (rand_err ? -1 : ret);
}
constchar *RAND_file_name(char *buf, size_t size)
{
char *s=NULL;
int ok = 0;
#ifdef __OpenBSD__struct stat sb;
#endifif (OPENSSL_issetugid() == 0)
s=getenv("RANDFILE");
if (s != NULL && *s && strlen(s) + 1 < size)
{
if (BUF_strlcpy(buf,s,size) >= size)
return NULL;
}
else
{
if (OPENSSL_issetugid() == 0)
s=getenv("HOME");
#ifdef DEFAULT_HOMEif (s == NULL)
{
s = DEFAULT_HOME;
}
#endifif (s && *s && strlen(s)+strlen(RFILE)+2 < size)
{
BUF_strlcpy(buf,s,size);
#ifndef OPENSSL_SYS_VMS BUF_strlcat(buf,"/",size);
#endif BUF_strlcat(buf,RFILE,size);
ok = 1;
}
else
buf[0] = '\0'; /* no file name */
}
#ifdef __OpenBSD__/* given that all random loads just fail if the file can't be * seen on a stat, we stat the file we're returning, if it * fails, use /dev/arandom instead. this allows the user to * use their own source for good random data, but defaults * to something hopefully decent if that isn't available. */if (!ok)
if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
return(NULL);
}
if (stat(buf,&sb) == -1)
if (BUF_strlcpy(buf,"/dev/arandom",size) >= size) {
return(NULL);
}
#endifreturn(buf);
}